Pulp-screen for paper-machines



(No Model.) SI LI GOUWLD.

Pulp Screen for Paper Machines.

No. 234,559. Patented Nov. 16, |880.

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UNITED STATES PATENT EEICE.,

SIMEON L. GOULD, OF GARDINER, MAINE.

PULP-SCREEN FOR PAPER-MACHINES.

SPECIFICATION forming part of Letters Patent No. 234,559, dated November 16, 1880,

' Application lcd August 10, 1880.

To all whom it may concern Be it known that L'SnviEoN L. GoULD, a citizen of the United States, residing at Gardiner, in the county of Kennebec and State of Maine, have invented certain new and useful Improvements in Pulp-Screens for Paper-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as 'will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specication.

This invention relates to a class of pulpscreens for paper-machinery now in general use in which metallic plates perforated with attenuated parallel slits are arranged in a horizontal plane in an open frame, to the front edge of which reciprocating vertical movements are imparted, in most cases, by resting upon the peripheries of toothed wheels, the action of each tooth being such as to alternately raise the screen and permit it to drop upon the next succeeding tooth, the continuous descents of the screen having the effect of precipitating the fine particles of pulp through the slits of the screen, leaving the refuse upon the top.

Heretofore the frame carrying the slotted screen-plates has been hinged at its rear side to the tank or box containing` it, and its front side caused to Vrise and fall by the action of the toothed wheels before named. This restricts the screening action of the screen, to a certain extent, since its rear side becomes coinparativelyinactive, and the purpose of my invention is to increase the effective capacity of the screen by imparting equal vertical movements to all part-s of it, and to this end I mount the frame of the screen upon yielding or elastic supports in such manner that it is susceptible of bodilyT vertical movements, while preserving a horizontal position, and I effect these vertical reciprocations of the screen by the employment of toothed wheels, as heretofore, or by links connecting the frame with cranks or eccentrics mounted upon an adjacent shaft.

The drawings accompanying this specification represent, in Figure 1, an isometric eleva- (No model.)

tion, and in Fig. 2 a vertical cross-section, of a screen containing' my improvements.

In these drawings, A represents the pulpscreen of a paper-making machine, the same consisting of the ordinary slotted plates B B, Ste., secured to the lower part, and constituting the bottom of an open frame, (l, the screen thus composed being disposed above the usual. shallow tank D, from which the screened pulp escapes to the inner apron of the machine, the standards or housings which uphold the screen and tank being shown at E E, and are united by suitable tie-rods F F.

In carrying my improvements intopractice I support the ends of the screen-frame G upon horizontal elastic or spring bars G G, each of which is confined at its ends to the upper part of the adjacent standard, these elastic supports permitting of short reciprocating vertical movements of the screen bodily with respect to the tank D. A second pair of elastic bars, H H, may be employed, secured to the upper edges of the ends of the screen-frame and parallel with the lower bars, the ends of this second pair of bars being secured to posts a c, erected upon the standards E E. These upper bars provide greater strength and security, as Well as additional elastic medium.

To effect thenecessary vertical reciprocations of the screen, I secure to the underside of eachl end of its frame aninclined lug or spur, b, each spur resting immediately over the upper surface of a vertical toothed wheel, c, affixed one to each end of a horizontal shaft, d, arranged centrally below the screen and mounted in bearings afxed to the standards E E.

Each wheel c has its periphery converted into a series of saw-teeth, c c, Ste., after the manner of pulp-screens now in common use, and these Wheels are rotated in the direction of their arrows. Hence, as the the teeth wipe in succession against the lugs b b, it follows that when in revolution they effect alternating or intermittent elevations of the screen, the descent of the latter being effected by its own gravity and the stress of the elastic bars.

In lieu of the toothed'wheels acting upon hangers of the screen-frame to effect elevations of the screen, eccentrics or cranks may be employed, secured to the shaft and connected with the screen-frame; but in this case IOO the descent of the screen would be more gradual.

In lieu of the elastic bars adapted to constitute a support for the screen, the latter may be supported upon spiral springs, either directly or through the agency of intervening bars; but I prefer the elastic bars before described.

I consider my present invention to consist, rst, in adapting` the screen to rise and fall bodily, while maintaining` a practically level position and, secondly, in mounting' the screen upon an elastic or yielding support, which,while securing` it in proper position,en ables it to rise and fall to the desired extent.

To determine the extent of the rise and fall ot' the screen, I employ screw-threaded rods f f, which are screwed downward through the ends of the screen-frame, and rest at their lower ends upon the top of the standards E E. By lowering" these rods with respect to the screen-frame, and thereby raising' the latter' with respect to the teeth of the wheels c c, the extent ot' rise and fall of the screen is varied; or in lieu ot' these rods eccentrics afxed to short shafts rotating` in bearings in the lower part ot' the ends of thef'rame may be employed to change the altitude of the screen, the eccentrics resting;` upon the tops ot' the standards.

I claiml. The screen as mounted upon an elastic support, by which it is susceptible of rising and falling bodily while preserving its horizontal position, substantially as explained.

2. The screen as mounted upon horizontal elastic bars, which constitute its support and permitit to rise and fall with a uniform movement, substantially as hereinbefore set forth.

3. The screw-rods, or their equivalents, in combination with the screen, the standards, and the toothed wheels, substantially as described.

4. The toothed wheels, or their equivalents, in combination with the screen, when serving to raise the entire screen bodily, substantially as and for purposes set forth.

5. The toothed wheels, in combination with the screen, and the elastic bars which support thelatter, substantially as herein described.

In testimony whereof I aix my signature in presence ot' two witnesses.

SIMEON L. GOUL'l).

Witnesses F. CURTIS, H. E. LODGE. 

